From 0306736e3afbe7be99d01e4d70d1a5f2e38c32c2 Mon Sep 17 00:00:00 2001 From: Jon Maloy Date: Tue, 15 Aug 2023 00:08:55 +0000 Subject: [PATCH] io: remove io watch if TLS channel is closed during handshake MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Jon Maloy RH-MergeRequest: 315: io: remove io watch if TLS channel is closed during handshake RH-Bugzilla: 2216504 RH-Acked-by: Peter Xu RH-Acked-by: Miroslav Rezanina RH-Commit: [1/1] 5f23602074b2edde0d445d529f07434bd156202d (redhat/rhel/src/qemu-kvm/jons-qemu-kvm-2) Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2216504 CVE: CVE-2023-3354 Upstream: Merged commit 10be627d2b5ec2d6b3dce045144aa739eef678b4 Author: Daniel P. Berrangé Date: Tue Jun 20 09:45:34 2023 +0100 io: remove io watch if TLS channel is closed during handshake The TLS handshake make take some time to complete, during which time an I/O watch might be registered with the main loop. If the owner of the I/O channel invokes qio_channel_close() while the handshake is waiting to continue the I/O watch must be removed. Failing to remove it will later trigger the completion callback which the owner is not expecting to receive. In the case of the VNC server, this results in a SEGV as vnc_disconnect_start() tries to shutdown a client connection that is already gone / NULL. CVE-2023-3354 Reported-by: jiangyegen Signed-off-by: Daniel P. Berrangé Signed-off-by: Jon Maloy --- include/io/channel-tls.h | 1 + io/channel-tls.c | 18 ++++++++++++------ 2 files changed, 13 insertions(+), 6 deletions(-) diff --git a/include/io/channel-tls.h b/include/io/channel-tls.h index 5672479e9e..26c67f17e2 100644 --- a/include/io/channel-tls.h +++ b/include/io/channel-tls.h @@ -48,6 +48,7 @@ struct QIOChannelTLS { QIOChannel *master; QCryptoTLSSession *session; QIOChannelShutdown shutdown; + guint hs_ioc_tag; }; /** diff --git a/io/channel-tls.c b/io/channel-tls.c index 9805dd0a3f..847d5297c3 100644 --- a/io/channel-tls.c +++ b/io/channel-tls.c @@ -198,12 +198,13 @@ static void qio_channel_tls_handshake_task(QIOChannelTLS *ioc, } trace_qio_channel_tls_handshake_pending(ioc, status); - qio_channel_add_watch_full(ioc->master, - condition, - qio_channel_tls_handshake_io, - data, - NULL, - context); + ioc->hs_ioc_tag = + qio_channel_add_watch_full(ioc->master, + condition, + qio_channel_tls_handshake_io, + data, + NULL, + context); } } @@ -218,6 +219,7 @@ static gboolean qio_channel_tls_handshake_io(QIOChannel *ioc, QIOChannelTLS *tioc = QIO_CHANNEL_TLS( qio_task_get_source(task)); + tioc->hs_ioc_tag = 0; g_free(data); qio_channel_tls_handshake_task(tioc, task, context); @@ -378,6 +380,10 @@ static int qio_channel_tls_close(QIOChannel *ioc, { QIOChannelTLS *tioc = QIO_CHANNEL_TLS(ioc); + if (tioc->hs_ioc_tag) { + g_clear_handle_id(&tioc->hs_ioc_tag, g_source_remove); + } + return qio_channel_close(tioc->master, errp); } -- 2.39.3